Halimede

A confirmed moon in the Neptune system.

Named · Neptune IX · S/2002 N 1

Snapshot 2026-09-09 · catalog 1.0.0

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Physical measurements

Mean radius
— No value in the admitted source set.
GM · gravitational parameter
— No value in the admitted source set.
Mass
— Mass requires an admitted GM estimate.
Mean density
— No value in the admitted source set.

Orbit descriptions

Mean elements describe an average orbit. They are not positions for a chosen date.

NEP104 · ecliptic plane · 2020-01-01.0 TDB
Semimajor axis
16,590,500 km
Sidereal period
1,879 days
Eccentricity
0.521
Inclination to reference plane
119.6°
Argument of periapsis
157.9°
Mean anomaly
135.8°
Ascending node
198.5°
Apsidal / nodal precession periods
5,395 / 5,156 years
Reference-plane pole RA / Dec
— / —°
Plane tilt to parent equator
—°
Reference center
Not specified in this summary sourceThe summary table identifies a parent system but does not explicitly specify the reference center for each solution. Do not infer a physical-primary center, especially for Pluto’s circumbinary moons.

Orientation

No supported orientation model in the admitted PCK source.

Identity & availability

Stable catalog ID
halimede
JPL / NAIF satellite ID
809
Names & designations
Halimede · S/2002 N 1
Discovery / rediscovery years
2002M. Holman, J.J. Kavelaars, T. Grav, W. Fraser, D. Milisavljevic

No validated dated trajectory admitted in catalog 1.0.0. Mean elements are not ephemerides.

No image or global texture admitted in this catalog release.No environment measurements admitted in this catalog release.

Sources & evidence

  1. JPL discovery circumstancestable tr[453] (zero-based); neptune / Halimede · References: IAUC 8047
  2. MPC planetary satellite listitems[55]; Neptune 9
  3. MPC satellite namesitems[63]; Neptune 9
  4. JPL mean orbital elements#sat_elem row ID=448; Neptune / Halimede / NAIF 809 · References: 43

Full catalog, uncertainty and source manifests · All Neptune moons · Moon model limits